A Pediatric Rheumatology Tissue Repository has been funded as part of a Rheumatic Disease Core Center. This core provides uniform acquisition and storage of human samples for research studies. In addition, the core allows for protocol-driven procurement and processing of samples. Because of the extensive sample requirements of the proposed P01 studies, we are proposing a supplement to this core. The purpose of the supplement will be to expand the collection of patient and control samples both locally and nationally to meet the needs of the four P01 projects. The scope of specimens needed for the P01 projects is extensive and can only be accomplished through collaborative efforts with additional clinical investigative sites (managed through the Administrative Core). The P01 studies require early time point collections from pauci, poly and systemic JRA patients, JAS, and adult ankylosing spondylitis patients, age and gender-matched controls, synovial fluid from JRA and JAS patients, as well as synovial tissue samples from JRA (systemic and poly) and control patients. The tissue core will ensure uniform sample collection locally and nationally which is imperative due to the sensitivity of gene expression measurements. The tissue core will handle samples in a manner to protect patient confidentiality and to meet all IRB requirements. Once collected the tissue core will be responsible for the distribution of samples to the individual projects or alternatively (following the priorities set forth by the administrative core) the tissue core will directly submit samples to the Affymetrix and flow cytometry cores for analysis. This tissue core is well suited to contribute to the success of the P01 projects.